Andrew Cuomo, the New York governor, warned on Saturday of “chaos and mayhem” if Donald Trump pressed ahead with a proposal for an enforced regional quarantine, saying such a move would be “a federal declaration of war”. “It’s a preposterous idea, frankly,” Cuomo told CNN on Saturday evening, hours after the president floated the idea of locking down parts of New York, New Jersey and Connecticut to try to slow the coronavirus spread. According to researchers at Johns Hopkins University, by Saturday night more than 116,000 Covid-19 cases had been recorded across the US with nearly 2,000 deaths. New York is by far the state heaviest hit. “Why you would want to just create total pandemonium on top of a pandemic I have no idea,” Cuomo said. “It’s totally opposite with what the president would want to do, work with the states, get the economy running and get some sense of stability. You wouldn’t at this point literally fracture the entire nation because it’s not just New York, New Jersey, Connecticut, it’s Louisiana and New Orleans. The numbers will continue to rise and every few days it’s going to be another hotspot.” He added: “It would be chaos and mayhem. If we start walling off areas all across the country it would just be totally bizarre, counterproductive, anti-American, anti-social.” Trump suggested imposing a quarantine earlier in the day, as he left the White House for a visit to Norfolk, Virginia. “We’re thinking about certain things. Some people would like to see New York quarantined because it’s a hotspot,” he said. “We might not have to do it, but there’s a possibility that sometime today we’ll do a quarantine, short-term, two weeks on New York. Probably New Jersey, certain parts of Connecticut. This would be an enforceable quarantine. I’d rather not do it, but maybe we need it.” Cuomo said Trump had not mentioned it when they spoke in the morning about a US navy hospital ship being deployed to New York City and four temporary hospital sites. “If the president was considering this, he would have called me,” Cuomo said, adding: “This would be a federal declaration of war on states.” He went on: “This is a civil war kind of discussion. I don’t believe that he could be serious, that any federal administration could be serious about physical lockdowns of states or parts of states. I don’t believe it’s legal, I believe it would be economic chaos, I don’t believe the American people would stand for it. “This is a time when the president says he’s trying to restart the economy. New York is the financial sector. You geographically restrict a state, you would paralyze the financial sector.” In an earlier press conference from Albany, the governor seemed blindsided by the president’s comments and a tweet in which Trump said: “I am giving consideration to a QUARANTINE of developing ‘hot spots’, New York, New Jersey, and Connecticut. A decision will be made, one way or another, shortly.” In Norfolk to say farewell to the USNS Comfort, Trump said “this great ship” was “a 70,000-ton message of hope and solidarity to the incredible people of New York, a place I know very well, a place I love.” But the president added: “We will stop at nothing to protect the health of New Yorkers, and the health of people in our country.” He also said any quarantine would “not apply to people such as truckers from outside the New York area. It won’t affect trade in any way.” Cuomo also continued to weigh the need for ventilators in New York, which with more than 52,000 positive coronavirus tests has more known infections than any other state. Trump this week told Fox News: “I don’t believe you need 40,000 or 30,000 ventilators.” At his Albany press conference, Cuomo held a “bag valve mask”, effectively a manual ventilator. “This is the alternative if you don’t have the ventilators,” he said. “We are actually buying these. We bought about 3,000. We’ve ordered an additional 4,000 of these bag valve masks. “We’re even talking about training national guard people to learn how to operate this device, which is relatively simple to operate but you need a lot of people to operate this 24-hours-a day for each patient. “If we have to turn to this device on any large-scale basis that is not an acceptable situation. We’re planning for that worst-case scenario.” The governor said Trump had approved temporary hospitals in the Bronx, Queens, Staten Island and Brooklyn. He also called for unified purchasing of medical supplies – either federally or a consortium among states. The USNS Comfort is expected in New York harbour on Monday as local medical centers face collapse. On Saturday there were reportedly nearly 27,000 known Covid-19 cases and 450 deaths in New York City. Cuomo said the state death toll had risen close to 800. The ship is the second US navy vessel deployed to a city battling coronavirus: the USNS Mercy docked in Los Angeles on Friday. On Twitter late on Friday, Trump continued to rail against Michigan governor Gretchen Whitmer, who reportedly claimed medical equipment suppliers were sending products to the federal government first. “I love Michigan, one of the reasons we are doing such a GREAT job for them during this horrible Pandemic,” Trump wrote. “Yet your Governor, Gretchen ‘Half’ Whitmer is way in over her head, she doesn’t have a clue. Likes blaming everyone for her own ineptitude!” On Saturday, Whitmer said in a tweet she had “a good call” with Vice-President Mike Pence. “We’ll keep working around the clock with [the Federal Emergency Management Agency] and the White House to get more of the personal protective equipment we need to keep Michiganders safe,” she wrote. “Stay home. Stay safe. Save lives.”